EP-OS 0435 374 has disclosed a process for controlling an automatic transmission where the gearshift from a first to a second reduction ratio is effected by a first clutch disengaging and a second clutch engaging. With the beginning of the gearshift, the pressure of the first clutch is lowered whereby the clutch is not allowed to slip. The curve of a turbine speed establishes the disengagement point of the first clutch. After the disengagement point is established, the slip of the second clutch is controlled in accordance with a time function.
A process for automatic control of an automatic transmission has also been described in the not pre-published German patent application P 44 24 456.8 of Jul. 12, 1994. The process consists of the following steps for an upshift: rapid-filling phase, filling-equalizing phase, load take-up phase, gradient-setting phase, sliding phase, gradient-breakdown phase and closing phase. A disadvantage of the aforementioned process is that a defective filling of the clutch to be engaged due to temperature, for example, is not taken into account.